Special cells called neurons use a chemical and electrical chain reaction to pass information along to various parts of the brain and nervous system. The genetic core, or nucleus, of a neuron is located in the cell body. But it's a neurons axons and dendrites that allow it to send and receive messages.

Branching dendrites take in signals in the form of chemicals. If they receive enough of the same signal, an electrical charge called an action potential flows down the axon to its tip. There, the charge triggers the release of chemicals that can cross gaps, known as synapses, which separate individual neurons.

These released chemicals can then jump-start the same process in the next cell down the chain. In this way, neurons can deliver messages any distance within the body – from head to toe.